The present invention relates to air flow systems for conducting air through an engine compartment of a vehicle, such as a truck.
In a typical truck, air flows through a grille of the truck and passes through a radiator for purposes of cooling fluid flowing through the radiator which is used in turn to cool an engine in an engine compartment.
In one conventional approach, the engine compartment is totally closed at the top by a hood and has side fenders enclosing at least portions of the sides of the engine compartment. Air entering through the radiator typically passes downwardly beneath the engine as the engine compartment is normally not closed from below and also escapes through the wheel wells of the vehicle. In these known approaches, insignificant quantities of the air which passes through the radiator flows along the side surfaces of the engine as it moves towards its escape route.
U.S. Pat. No. 1,984,077 to Morrison discloses a vehicle having a hood with side panels. The side panels are provided with openings covered by doors which may be manually opened or closed to adjust air flow through the doors. A similar opening is provided at each side of a cowl of the vehicle. The wheels of the vehicle illustrated in this patent have a fender but are otherwise exposed. The side panels of the hood extend downwardly between the fender and top rear quadrant of the wheel. With the arrangement disclosed in Morrison, one must depend upon the operator of the vehicle or another person opening the doors in order to provide additional engine compartment ventilation. Also, if the forward-most door or doors in this patent is opened, air may exit beneath the vehicle and through such openings rather than passing along the engine. Also, the doors in Morrison project outwardly and into the air stream passing along the hood when open, thereby increasing the air resistance of the vehicle when traveling in a forward direction.
U.S. Pat. No. 4,549,762 to Burk et al. discloses a ventilation arrangement for discharging hot air from the engine compartment of a car. In this arrangement, an enclosed cavity is formed in the wheel well of the vehicle. This cavity is accessible through circular openings communicating with the engine compartment. Cavity exit openings are provided along the lower side portions of the outer fender panel overlying the cavity and also through circular openings in a rear panel bounding the cavity. These latter rear panel openings communicate with the exterior of the vehicle through a crack between the door and fender. In the Burk et al. patent, air flows in a tortuous path from the engine compartment to an exit, thereby decreasing the efficiency of the air flow.
U.S. Pat. No. 3,064,747 to Barenyi discloses portions of a car with air flow guides, some of which communicate with an engine compartment. The figures of this patent disclose air flow pathways through which air is supplied or discharged from the engine compartment. Apparently the car of the Barenyi patent is air-cooled, as air flows directly into the engine compartment through a gap between the hood and front panel without passing through a radiator. A complex arrangement of gaps and air flow paths is provided in the Barenyi patent.
U.S. Pat. No. 5,275,249 to Nelson discloses a vehicle with a hood having raisable hood plates to provide rear facing engine compartment ventilation.
Although a number of prior art approaches are known for providing increased ventilation to an engine compartment, a need exists for an improved underhood air flow system.